# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
from typing import Optional

import numpy as np
import pytest
import torch

from vllm.config import ModelConfig, ParallelConfig, VllmConfig
from vllm.multimodal.cache import (MultiModalCache,
                                   MultiModalProcessorCacheItem,
                                   MultiModalProcessorCacheItemMetadata,
                                   engine_receiver_cache_from_config,
                                   processor_cache_from_config)
from vllm.multimodal.hasher import MultiModalHasher
from vllm.multimodal.inputs import (MultiModalFieldElem, MultiModalKwargsItem,
                                    MultiModalKwargsItems,
                                    MultiModalSharedField)
from vllm.multimodal.processing import PromptInsertion
from vllm.multimodal.registry import MultiModalRegistry


def _dummy_elem(
    modality: str,
    key: str,
    size: int,
    *,
    rng: Optional[np.random.RandomState] = None,
):
    if rng is None:
        data = torch.empty((size, ), dtype=torch.int8)
    else:
        data = torch.from_numpy(rng.randint(4, size=(size, ), dtype=np.int8))

    return MultiModalFieldElem(
        modality=modality,
        key=key,
        data=data,
        field=MultiModalSharedField(1),
    )


def _dummy_item(
    modality: str,
    size_by_key: dict[str, int],
    *,
    rng: Optional[np.random.RandomState] = None,
):
    return MultiModalKwargsItem.from_elems([
        _dummy_elem(modality, key, size, rng=rng)
        for key, size in size_by_key.items()
    ])


def _dummy_items(
    size_by_key_modality: dict[str, dict[str, int]],
    *,
    rng: Optional[np.random.RandomState] = None,
):
    return MultiModalKwargsItems.from_seq([
        _dummy_item(modality, size_by_key, rng=rng)
        for modality, size_by_key in size_by_key_modality.items()
    ])


# yapf: disable
@pytest.mark.parametrize(
    ("item", "expected_size"),
    [
        (_dummy_item("a", {"a1": 100}), 100),
        (_dummy_item("a", {"a1": 100, "a2": 110}), 210),
        (_dummy_items({"a": {"a1": 100, "a2": 110}, "b": {"b1": 120, "b2": 130}}), 460),  # noqa: E501
        (_dummy_items({"a": {"a1": 100, "a2": 110}, "b": {"b1": 120, "b2": 130}}).get_data(), 460),  # noqa: E501
    ],
)
# yapf: enable
def test_cache_item_size(item, expected_size):
    cache = MultiModalCache.get_lru_cache(2048, type(item))

    cache[""] = item
    assert cache.currsize == expected_size

    prompt_update = PromptInsertion("dummy", "target", "insertion") \
        .resolve(0)

    cache[""] = MultiModalProcessorCacheItem(item, [prompt_update])
    assert cache.currsize == expected_size

    cache[""] = MultiModalProcessorCacheItemMetadata(item, [prompt_update])
    assert cache.currsize == expected_size


def _create_vllm_config(
    *,
    mm_processor_cache_gb: float,
    enable_ipc: bool,
):
    return VllmConfig(
        model_config=ModelConfig(mm_processor_cache_gb=mm_processor_cache_gb),
        parallel_config=ParallelConfig(
            data_parallel_size=1 if enable_ipc else 2),
    )


def _compare_caches(
    config_0: VllmConfig,
    config_1: VllmConfig,
    *,
    item_capacity: int = 8,
    hit_rate: float = 0.5,
    max_items_per_iter: int = 3,
    is_cached_calls_per_iter: int,
    n_iter: int = 100,
    seed: int = 0,
):
    mm_registry = MultiModalRegistry()
    cache_0_p0 = processor_cache_from_config(config_0, mm_registry)
    cache_0_p1 = engine_receiver_cache_from_config(config_0, mm_registry)
    cache_1_p0 = processor_cache_from_config(config_1, mm_registry)
    cache_1_p1 = engine_receiver_cache_from_config(config_1, mm_registry)

    cache_size_gb = max(
        config_0.model_config.mm_processor_cache_gb,
        config_1.model_config.mm_processor_cache_gb,
    )
    item_size_gb = int(cache_size_gb / item_capacity)

    rng = np.random.RandomState(seed)
    all_items = [
        _dummy_item("item", {"key": item_size_gb}, rng=rng)
        for _ in range(int(item_capacity / hit_rate))
    ]
    all_hashes = [
        MultiModalHasher.hash_kwargs(item=item.get_data())
        for item in all_items
    ]

    # Should not be used since there is nothing to convert to text
    prompt_update = PromptInsertion("dummy", "target", "insertion")

    for it in range(n_iter):
        num_items_to_select = rng.randint(0, max_items_per_iter)
        item_idxs_to_select = rng.choice(len(all_items), num_items_to_select)

        selected_items = [all_items[idx] for idx in item_idxs_to_select]
        selected_hashes = [all_hashes[idx] for idx in item_idxs_to_select]

        if cache_0_p0 is None:
            cache_0_p0_out = selected_items
        else:
            for _ in range(is_cached_calls_per_iter):
                cache_0_p0.is_cached(selected_hashes)
            cache_0_p0_out = [
                item for item, _ in cache_0_p0.get_and_update(
                    [(item, prompt_update.content) for item in selected_items],
                    selected_hashes,
                )
            ]

        if cache_1_p0 is None:
            cache_1_p0_out = selected_items
        else:
            for _ in range(is_cached_calls_per_iter):
                cache_1_p0.is_cached(selected_hashes)
            cache_1_p0_out = [
                item for item, _ in cache_1_p0.get_and_update(
                    [(item, prompt_update.content) for item in selected_items],
                    selected_hashes,
                )
            ]

        if cache_0_p1 is None:
            cache_0_p1_out = cache_0_p0_out
        else:
            cache_0_p1_out = cache_0_p1.get_and_update(cache_0_p0_out,
                                                       selected_hashes)

        if cache_1_p1 is None:
            cache_1_p1_out = cache_1_p0_out
        else:
            cache_1_p1_out = cache_1_p1.get_and_update(cache_1_p0_out,
                                                       selected_hashes)

        assert cache_0_p1_out == cache_1_p1_out, f"Failed at {it=}"


@pytest.mark.parametrize("is_cached_calls_per_iter", [1, 2, 3])
def test_ipc_enable_disable_consistency(is_cached_calls_per_iter):
    cache_size_gb = 1 / (1 << 20)

    vllm_config_ipc_enabled = _create_vllm_config(
        mm_processor_cache_gb=cache_size_gb,
        enable_ipc=True,
    )
    vllm_config_ipc_disabled = _create_vllm_config(
        mm_processor_cache_gb=0,
        enable_ipc=False,
    )
    vllm_config_cache_disabled = _create_vllm_config(
        mm_processor_cache_gb=cache_size_gb,
        enable_ipc=True,
    )

    _compare_caches(
        vllm_config_ipc_enabled,
        vllm_config_ipc_disabled,
        is_cached_calls_per_iter=is_cached_calls_per_iter,
    )
    _compare_caches(
        vllm_config_ipc_disabled,
        vllm_config_cache_disabled,
        is_cached_calls_per_iter=is_cached_calls_per_iter,
    )
    _compare_caches(
        vllm_config_cache_disabled,
        vllm_config_ipc_enabled,
        is_cached_calls_per_iter=is_cached_calls_per_iter,
    )
